DIY Self-Install in San Diego - 7.84 kW for < $1.30 / W

[sensij]

Thanx for the update. Break any tiles yet ?

I had picked up a stack of free tiles from someone on Craigslist, in anticipation of breaking a few. Those tiles aren't an exact color match, so I ground a bunch of them for clearance for the hooks and swapped them in as I was installing the attachments. No one will ever see the color difference under the array, and by saving the tiles I pulled out, I've got good replacements for more visible parts of the roof. Anyway, the tiles I swapped in are older, and seem more fragile. I've broken 3 of them so far. If the entire roof had been tiled with them, this would have been a very different experience.

So far, so good, but how are you gonna' get under the array when your curiosity gets the better of you ??

The bottom of the rails are 3.75" above the surface of the lower tile, and the rail itself is 3" tall, so I've got a good 5" or so clearance underneath when I'm coming at it from above. Hopefully enough room to slide in some surface mount temperature sensors at some point That said, this array is going to be a nightmare to service [S]if[/S] when the optimizers eventually fail. Of the 28 panels going up, 12 will be inaccessible except by removing another panel. Because it is close to the edge of the roof, the bottom row is only accessible from above, and I'm not sure I can even reach the lower clamping screw from above... they are all getting installed from the side as the row gets built out. I guess a longer handled ratchet would be needed. I can tweak optimizer position to maybe make a couple of them more accessible, but mostly, I'm just hoping for no infant mortality so it will be a long time before I have to deal with any of it.

I had toyed with the idea of lowering the rail clearance near the lower edge of the roof to squeeze another degree or two of tilt out of it, but at this point, it is easier to just use a standard spacer block everywhere, and I want to get it done.

[J.P.M.]

Thanx for the update. Break any tiles yet ?

So far, so good, but how are you gonna' get under the array when your curiosity gets the better of you ??

[sensij]

Haven't updated in a few weeks, so some more pictures are below. All attachments are done, rails are up, and I've got the conduit penetration in and flashed. I'm using a Wiley ACE-2P for the junction box (found reference to it in a thread a couple years ago, thank you Amy@altE , slightly more expensive than a generic junction box with waterproof connectors would have been, but not by much. The first three panels went up tonight, it will take another week or so to get the rest up. Still some more conduit work to do as well. I gave up on the SE7600H-US, and have a SE7600A-US coming instead.

tile removal.png


rails.png






conduit base flashing.png

conduit base flashing with paper.png

conduit tile.png



conduit finished.png

[J.P.M.]

05/01/17, 1436 hrs: thanx for the info.

[sensij]

Here are a few more pictures of the hook installation. I've got 19 of 34 up so far, getting about 4 done per hour in the time I've been able to find to work on this. At this point I should probably include my electric bill each month in the total accounting of cost each month (on the assumption that paying someone would have resulted in a completed system by now). I'm trying to avoid hiring babysitters to get a more focused run at this, but we'll see.

I picked up some replacement rooftiles listed for free on Craigslist, and have been swapping them in. They aren't a perfect color match, and seem somewhat degraded, but by putting them under the array, I can keep the good ones I pull out for use in other repairs. I've found one catastrophically cracked tile on another part of the roof, and a few that are chipped along the seam that I'll probably leave alone for now.

Prying out the tile isn't pictured here. I prop up the tile to the left with a small prybar, then pop up the nail slightly by lifting the tile I want to remove. A cat's claw and some elbow grease are used to reach under the upslope tile and pull out the nail by the exposed head.

Find and mark rafter with a stud finder, then drill the 7/32" pilot holes: PilotHoles.JPG




After backfilling the hole with Geocell 2300 and mounting the hook. Note the twisted off screwhead. I've adjusted my technique to avoid it sometimes, but am not too worried about it. AttachedHook.JPG




U-shaped bead of Geocel applied to the back of the flashing before installation. A layer of roofing paper is also applied to further protect the uphill edge, but I'm no longer using nails in the corners, or pulling up any more adjacent tiles than necessary to drill the holes. Flashed.JPG




Bottom of the tile is ground open to give clearance for the hook. Tileaftergrinding.JPG




And, finished. You can see the chalk lines I had used to ballpark the location of the rafter and the right row of tile to locate the rail. Finished.JPG

[J.P.M.]

No, my rafters are generally continuous and not overlapped or staggered. There is some sub-structure framing that causes a substantial change in rafter pattern in a couple of spots. I can post some pictures for those interested.



Nope, no roofer's cement or other sealant on these nails. 100% of protection for these penetrations is provided by the tile layer above.



I was cautious my first few trips up a month or two ago to take measurements for the permit application, using the techniques you've described here, but at this point I just walk freely (but not stupidly). I keep looking for a crack, but the next one I make will be the first one.



I think my roof will be a good test for how long it takes for that condensation to do damage here. Thousands of holes protected only by the nail filling them. Clearly, the roof is better protected with paper than without (I'm not questioning that at all). It is just that it is hard to look at all those tile nails and think of the roof as having been impervious until I came along with my lag screws and PV mounts.



No holes are visible when the concrete tiles are installed. With the tile removed, I bibbed with paper over the few new nails I put in when I was first following the instructions after step 5, but I have stopped putting in new nail holes to avoid this problem completely. Their function isn't so clear... there is nowhere for the aluminum flashing to go, even if the sealant that adheres it to the paper eventually lets go. Maybe the nails are needed for a steeper roof with more clearance between the deck and the tile? Here is the pic from the manual that shows them. nails.JPG









It is a weird use of screws... the screwhead isn't the functional end... the tip is. The quickhook mates with the mounting base like a slide and gib. The screw works sort of like a set screw in that once you drive the screw in far enough, the tip pushes on the base and forces the hook up against the gib, securing it. In other words, if the head were tightened against its mating face like a normal fastener, the screw wouldn't be doing anything at all (for that matter, the mating face in this case isn't even flat). A screw that is twice as long would be just as functional (but would interfere with the flashing). The picture from the instructions below, hopefully I'm describing this clearly enough. I'm sure they aren't supposed to shear, and the instructions warn against using an impact gun, but I'd rather have them too tight than not tight enough, you know? Medium torque on my drill doesn't drive them at all. screw.JPG









From a common sense perspective, the concrete tile nail holes worry me much more than what I'm doing with these mounts, but I don't think I'm going to lose sleep over any of it. I'll definitely post some more pictures soon, but I understand better now why Solarix has taken the position he has on the suitability of some of Quickmount PV's competitors.

Edit: In any case, J.P.M., thanks for the comments.

You're welcome. I reviewed the instruct. & video. Looking at them again later, that set screw arrangement seems a bit funky to me in that it might loosen up over time/temp. excursions and from wind vibration with not much, if any access or easy inspection. I guess I would have done those by hand and found some way to rig a (removable ?) locking nut/etc, on that set screw as wobbly insurance.

I'd also figure out a way to slide a piece of AL that's wider than the AL flashing and slide it under the paper layer above, overlapping the nail holes in the flashing cover and secure the added AL piece w/ roof cement/adhesive. Reason: Looks to me that the upper horizontal edge of the flashing can be a leak point if left as fig. 5 shows and water somehow gets under the tiles above.

On the nail holes for paper and for tile: When I had my roof serviced before array install, I used 2/3 overlapping layers of paper w/ the top layer covering the lower nail holes except for the uppermost layer at the peak, and all the nail holes in the paper supplied w/plastic collars and roof cement on top of and around the collars. Then, I had the tile nail holes/heads caulked w/silicon.

FWIW, it's been my experience that if I haven't seen water damage/spots on the inside of the roof, the existing stuff hasn't failed yet, and probably won't anytime soon.

Thanx for the response.

Add: Forgot to mention: Forget needed to spend much time looking for cracks. In all likelihood, if a tile fails from foot traffic, you'll know it in a millisecond or two from the noise and impact of the failure. Like glass, most concrete tiles have an abrupt yield curve. Plan and expect to break a tile or two.

[sensij]

1.) On rafter location: If you can see the rafter from the interior, this doesn't matter., but sometimes, or more often, a rafter is not one continuous piece. If so, and thus overlapped/staggered, that will knock the rafter C.L. by one width left or right from the under-eve rafter location.

No, my rafters are generally continuous and not overlapped or staggered. There is some sub-structure framing that causes a substantial change in rafter pattern in a couple of spots. I can post some pictures for those interested.

2.) On your point one, that's a pretty standard way to do tile fixation with the use of roof cement /etc. over the nail holes and then the sealed nail hole covered by the tile above. As long as the tile above is intact, it's OK.

Nope, no roofer's cement or other sealant on these nails. 100% of protection for these penetrations is provided by the tile layer above.

Also, and pardon me if this sounds condescending, but, in case you don't know, the way to walk on flat concrete tiles and (hopefully) minimizing breakage is to step on a tile so that the C.L. of your foot is parallel to the bottom edge of the tile as much as possible, while staying away from the tile edges as much as possible. Some dog ears and a break or two will likely happen anyway.

NEVER step on the center of a tile. Stay away from the edges as well. Sounds like a PITA, but you'll get the hang and the habit of it after a trip or two to the roof, if you haven't got it already.

I was cautious my first few trips up a month or two ago to take measurements for the permit application, using the techniques you've described here, but at this point I just walk freely (but not stupidly). I keep looking for a crack, but the next one I make will be the first one.

3.) Tiles are the initial water barrier, but the paper underneath is the primary protection from condensation, bugs, and other infiltration.

I think my roof will be a good test for how long it takes for that condensation to do damage here. Thousands of holes protected only by the nail filling them. Clearly, the roof is better protected with paper than without (I'm not questioning that at all). It is just that it is hard to look at all those tile nails and think of the roof as having been impervious until I came along with my lag screws and PV mounts.

4.) On your point 4, and as a general rule of thumb, if you can see a penetration - a nail, bolt , staple, etc., water that was airborne from above can get at it. If an exposed penetration gets sealed, but not covered, it'll leak someday. If the flashing penetrations are raised so that all gaps are above any possible standing or flowing water level, and covered by tile as well as sealed/caulked, you're probably OK.

No holes are visible when the concrete tiles are installed. With the tile removed, I bibbed with paper over the few new nails I put in when I was first following the instructions after step 5, but I have stopped putting in new nail holes to avoid this problem completely. Their function isn't so clear... there is nowhere for the aluminum flashing to go, even if the sealant that adheres it to the paper eventually lets go. Maybe the nails are needed for a steeper roof with more clearance between the deck and the tile? Here is the pic from the manual that shows them. nails.JPG

5.) On your point 6, They're tight now, but if there's any chance that the joint can come loose/rock itself out from thermal cycling or cyclic wind loads because of the absence of the (snapped) head, that may be a future problem. A blinding flash of the obvious: They shouldn't be snapping off. If the snapped part was part of what ensured continuing joint integrity, I'd be concerned.

It is a weird use of screws... the screwhead isn't the functional end... the tip is. The quickhook mates with the mounting base like a slide and gib. The screw works sort of like a set screw in that once you drive the screw in far enough, the tip pushes on the base and forces the hook up against the gib, securing it. In other words, if the head were tightened against its mating face like a normal fastener, the screw wouldn't be doing anything at all (for that matter, the mating face in this case isn't even flat). A screw that is twice as long would be just as functional (but would interfere with the flashing). The picture from the instructions below, hopefully I'm describing this clearly enough. I'm sure they aren't supposed to shear, and the instructions warn against using an impact gun, but I'd rather have them too tight than not tight enough, you know? Medium torque on my drill doesn't drive them at all. screw.JPG








From a common sense perspective, the concrete tile nail holes worry me much more than what I'm doing with these mounts, but I don't think I'm going to lose sleep over any of it. I'll definitely post some more pictures soon, but I understand better now why Solarix has taken the position he has on the suitability of some of Quickmount PV's competitors.

Edit: In any case, J.P.M., thanks for the comments.

[J.P.M.]

I've been recovering from a sprained ankle, but was finally able to get up on the roof this weekend and start installing attachments. I was successful using a cheap stud to find the rafters, and double-checked inside the attic that none of them were splitting. The rafter ends are visible in the eave from underneath, and I could find and mark them from the roof by reaching around and feeling beneath the gutter. From there, shooting a line up the roof gets close enough to know which tile to pull up. I can't confirm that I'm really in the center 1/3rd of the rafter, but every bolt has gone in and bit nicely so far. I didn't believe the stud finder on one rafter that wasn't indicating, and put a couple of exploratory holes in the roof that I still need to go seal, but I should have trusted it. When looked inside that attic later I could see that indeed that rafter isn't there, it ends on some other trusswork lower in the roof.

I like the Quickmount PV Quickhook system, but their flashing process feels like some combination of overkill and marketing, at least for my roof. Some observations:

1) Every concrete tile on my roof has a nail holding it directly to the paper covered sheathing, no battens. The nails are overlappped by the tile above, but otherwise, there is no sealing or additional flashing. Any water blowing in under the tile has thousands of paths through the underlayment to the wood. I've been looking for cracked tiles... they support me walking on them just fine, but I found a broken one on another section of roof. The tiles are clearly the primary water barrier in this construction, and I'll replace the fully cracked ones or seal the corner-cracked ones before I'm done this project.

2) The installation instructions for the quickhook requires two lag bolts per mount. I'm predrilling the holes and using Geocel 2300 to backfill the hole to get good squeezeout when tightening down the bolts. This compression seal + sealant combination seems impervious to water, at least compared to the other nail holes.

3) A piece of aluminum flashing is used over the base mount, with a U-shaped bead of sealant, to further reduce the chance of water getting to the lag screw holes. So far, so good.

4) The instructions say to use a roofing nail in each of the upper corners of the flashing to pin it to the roof. What? So, to protect the two compression sealed lag bolt holes, I'm going to make two more nail holes that rely only on paper to be sealed? The instructions don't even mention using sealant on these holes.

5) To protect the nail holes and seal the outer edges of the aluminum flashing, the instructions recommend either the three-course method or bibbing the mount with more paper. Either of these methods requires pulling up 3-5 more of the surrounding tiles to get full access to the boundaries. Every one of those tiles that comes out leaves an exposed nail hole behind that needs to be filled or covered, and disturbs one more layer of neighboring tiles.

6) The phillips head screw that locks the hook to the base doesn't seem to be well designed. It self taps through the hook, but the torque required to drive it caused about half of the screw heads to shear off when they hit the base. They are locked at that point so I'm not so worried about the integrity of the attachment, but If I ever needed to remove any of the hooks, they would need to be drilled out.

7) Grinding back the tile to allow the hook to pass through the bottom is easy with the recommended angle grinder + tuck point wheel, and leaves the tile otherwise intact.

In terms of risk reduction, I just don't see how all the extra work to achieve the installation per the instructions is better than two compression sealed bolt holes, with the extra piece of aluminum flashing to divert the water away. After the first couple attachments, I stopped with the extra nails to hold the aluminum flashing in place, and am bibbing as well as I can without tearing up extra tiles.

Respectfully:

1.) On rafter location: If you can see the rafter from the interior, this doesn't matter., but sometimes, or more often, a rafter is not one continuous piece. If so, and thus overlapped/staggered, that will knock the rafter C.L. by one width left or right from the under-eve rafter location.

2.) On your point one, that's a pretty standard way to do tile fixation with the use of roof cement /etc. over the nail holes and then the sealed nail hole covered by the tile above. As long as the tile above is intact, it's OK.

Also, and pardon me if this sounds condescending, but, in case you don't know, the way to walk on flat concrete tiles and (hopefully) minimizing breakage is to step on a tile so that the C.L. of your foot is parallel to the bottom edge of the tile as much as possible, while staying away from the tile edges as much as possible. Some dog ears and a break or two will likely happen anyway.

NEVER step on the center of a tile. Stay away from the edges as well. Sounds like a PITA, but you'll get the hang and the habit of it after a trip or two to the roof, if you haven't got it already.

3.) Tiles are the initial water barrier, but the paper underneath is the primary protection from condensation, bugs, and other infiltration.

4.) On your point 4, and as a general rule of thumb, if you can see a penetration - a nail, bolt , staple, etc., water that was airborne from above can get at it. If an exposed penetration gets sealed, but not covered, it'll leak someday. If the flashing penetrations are raised so that all gaps are above any possible standing or flowing water level, and covered by tile as well as sealed/caulked, you're probably OK.

5.) On your point 6, They're tight now, but if there's any chance that the joint can come loose/rock itself out from thermal cycling or cyclic wind loads because of the absence of the (snapped) head, that may be a future problem. A blinding flash of the obvious: They shouldn't be snapping off. If the snapped part was part of what ensured continuing joint integrity, I'd be concerned.

Compression sealed holes are fine as long as the compressive stress of the seal is intact and the compressive elements maintain their initial properties. As long as such joints are above any expected water level and covered, they may well last as long as the panels. Compression sealing that relies on flexible material like neoprene/foam/etc. is a form of what's called self energizing gasketed joint. If the gasketing material looses flexibility, expect the joint to loosen up.

On water ingress, or preventing it, think like water and see if you can figure out a way to get past a design and then modify as necessary. You'll be fine. You have common sense.

[sensij]

I've been recovering from a sprained ankle, but was finally able to get up on the roof this weekend and start installing attachments. I was successful using a cheap stud to find the rafters, and double-checked inside the attic that none of them were splitting. The rafter ends are visible in the eave from underneath, and I could find and mark them from the roof by reaching around and feeling beneath the gutter. From there, shooting a line up the roof gets close enough to know which tile to pull up. I can't confirm that I'm really in the center 1/3rd of the rafter, but every bolt has gone in and bit nicely so far. I didn't believe the stud finder on one rafter that wasn't indicating, and put a couple of exploratory holes in the roof that I still need to go seal, but I should have trusted it. When looked inside that attic later I could see that indeed that rafter isn't there, it ends on some other trusswork lower in the roof.

I like the Quickmount PV Quickhook system, but their flashing process feels like some combination of overkill and marketing, at least for my roof. Some observations:

1) Every concrete tile on my roof has a nail holding it directly to the paper covered sheathing, no battens. The nails are overlappped by the tile above, but otherwise, there is no sealing or additional flashing. Any water blowing in under the tile has thousands of paths through the underlayment to the wood. I've been looking for cracked tiles... they support me walking on them just fine, but I found a broken one on another section of roof. The tiles are clearly the primary water barrier in this construction, and I'll replace the fully cracked ones or seal the corner-cracked ones before I'm done this project.

2) The installation instructions for the quickhook requires two lag bolts per mount. I'm predrilling the holes and using Geocel 2300 to backfill the hole to get good squeezeout when tightening down the bolts. This compression seal + sealant combination seems impervious to water, at least compared to the other nail holes.

3) A piece of aluminum flashing is used over the base mount, with a U-shaped bead of sealant, to further reduce the chance of water getting to the lag screw holes. So far, so good.

4) The instructions say to use a roofing nail in each of the upper corners of the flashing to pin it to the roof. What? So, to protect the two compression sealed lag bolt holes, I'm going to make two more nail holes that rely only on paper to be sealed? The instructions don't even mention using sealant on these holes.

5) To protect the nail holes and seal the outer edges of the aluminum flashing, the instructions recommend either the three-course method or bibbing the mount with more paper. Either of these methods requires pulling up 3-5 more of the surrounding tiles to get full access to the boundaries. Every one of those tiles that comes out leaves an exposed nail hole behind that needs to be filled or covered, and disturbs one more layer of neighboring tiles.

6) The phillips head screw that locks the hook to the base doesn't seem to be well designed. It self taps through the hook, but the torque required to drive it caused about half of the screw heads to shear off when they hit the base. They are locked at that point so I'm not so worried about the integrity of the attachment, but If I ever needed to remove any of the hooks, they would need to be drilled out.

7) Grinding back the tile to allow the hook to pass through the bottom is easy with the recommended angle grinder + tuck point wheel, and leaves the tile otherwise intact.

In terms of risk reduction, I just don't see how all the extra work to achieve the installation per the instructions is better than two compression sealed bolt holes, with the extra piece of aluminum flashing to divert the water away. After the first couple attachments, I stopped with the extra nails to hold the aluminum flashing in place, and am bibbing as well as I can without tearing up extra tiles.

[sensij]

My SWAG is you'll do a bit better @ new location - less marine layer - but your A/C demand will be higher due to amb. temps.

No central air conditioner at either this residence or the last, although this one is plumbed/wired for it. At the old house, we ran a window A/C when it got hot, but I think we may just get by with fans here... we've got a better breeze, two stories with high ceilings. July - Sept last year might have been more moderate than some years though, so we'll see. Window A/C's won't comply with the CC&R's here.

Nothing from the city on roof vents, again, based on what I'm seeing on the roofs around me, I'm going to work off the assumption that the city doesn't mind if the low profile attic vents end up under the array. If additional venting becomes required by the inspector, I'll adjust at that time.

[J.P.M.]

Thank you for the update. Any info to share on what the city had to say about vent locations, standoffs, etc., if anything ?

[J.P.M.]

Agreed. My 3.12 kW system in 92111 with the same azimuth and tilt as the planned system produced about 5.35 MWh from July 2015 to June 2016 with some shade, for a 1.72 ratio and perhaps less sun and wind (single story vs two story) than I'll get here in 92129. After the rainy season we've had, that system will probably be closer to 5 MWh over that period in 2016-2017.

My SWAG is you'll do a bit better @ new location - less marine layer - but your A/C demand will be higher due to amb. temps.

[sensij]

I've been meaning to up this thread for a couple weeks, and have been slipping in comments on progress in other thread. Some major milestones:

1) Permit has been issued
2) Approval from the HOA to move forward has been received
3) All major equipment has been delivered from Tandem solar, except the inverter, which I've intentionally delayed.

A bit more about the design + permit process.

I did most of the design work and first draft of the plans using the 30 day free trial on solardesigntool as well as Iron Ridge's online design tool. Early on, I had hoped that the long spans suggested by the Ironridge tool might mean I could get away with fewer roof attachments and penetrations. However, the CA design guide and San Diego's own expedited permit guidelines require a max span of 72", unless structural engineering is provided to justify a longer span. So, 72" spans it is.

The CAD in the design software was OK, but I found that working in more common modelling software helped me use the roof dimensions I measured more accurately, and I finalized the layout that way. This encouraged me to move away from the Hanwha Q.Cell G4.1 panels I had been considering to the Canadian Solar panels, because they were smaller and required only one ridge setback waiver, while the Q.Cells design would have required a waiver for two ridges and one rake to get the same power. There was no "waiver" process... I just submitted the plans as attached, and whoever is responsible for evaluating the setbacks was apparently OK with the design.

I submitted the permit application electronically on a Thursday night, and received no response from the city until I got a letter in the mail the next Thursday detailing a couple of small tweaks that were needed. The changes needed:

1) Add a rapid shutdown plaque to the placards listing. (I had used a 2011 NEC permit submission for my source material on this, which hadn't required rapid shutdown)
2) Clarify the grounding - the default single line diagram produced by the design tool was confusing, and needed to be cleaned up.
3) For integrated grounding, provide documentation to show module + racking compatibility.

I resubmitted that night, and got full approval and issuance the next day, after I paid the invoice online.

San Diego's online permit system is kind of neat, lots of public record information is available through it. Even though my original permit submission had only generated a response by mail, the online system has a map that shows all active and completed permits, and I found that a project had been quickly created for my system so I knew it was received and in process.

The permit cost $432. It would have been $175 less if it had been prepared by someone with professional certification (San Diego has a documented process to obtain this certification). It would have cost $350 to outsource the permit, so only a net $175 difference if I hadn't done it myself. That $175 would probably have been money well spent, it took a lot of time to customize the permit templates that had been found or produced by the design software to make them correct for my system.

A copy of the plans as approved, with some personal information stripped out, are available at the dropbox link below. They were too big to attach directly to this post. The only other change I've noticed is that the 1/2" conduit called out for the run from the inverter to the MSP is too small, I'll be using 3/4" there.

Less than a week after the permit was issued, I got a letter inviting me to come to the city office and pick up the permit. That was straightforward, in and out in 5 minutes when I dropped in on my way into work.

https://www.dropbox.com/s/ptmq6qru8c...check.pdf?dl=0

[sensij]

My est. SAM output is 9,469 kWh/yr. less ~ 3-4 % late afternoon shade. Considering weather/irradiance variability, I seem to be making that.

FWIW, 9,469/5,232 - .04 = 1.81 - .04 = ~ 1.77.

13,600 kWh/yr./7,840 W = 1.73 seems doable around here for a 7.84 kW array.

Agreed. My 3.12 kW system in 92111 with the same azimuth and tilt as the planned system produced about 5.35 MWh from July 2015 to June 2016 with some shade, for a 1.72 ratio and perhaps less sun and wind (single story vs two story) than I'll get here in 92129. After the rainy season we've had, that system will probably be closer to 5 MWh over that period in 2016-2017.

[sensij]

NOMB, but last time I checked the S.D. building code, vents couldn't be covered by arrays. maybe I missed the part about flush mounted vents. I'd find out who the AHJ inspector is and ask. No harm, no foul.

It is a fair concern. On one hand, both the California Solar Permitting Guidebook and the County of San Diego's minimum construction guidelines provide code references on staying clear of plumbing and exhaust vents, but omit roof vents. guidebook.JPG
County.PNG




On the other hand, the City of San Diego's template and inspection guidelines are more restrictive, but don't provide a code reference. They are the AHJ.
city.JPG
inspect.JPG



In other installations on my neighborhood with similar roofing material and venting systems, it does not appear the the low profile vents have been a problem, but while I'm up on the roof and in the attic, I'll be looking for any mitigation options available should the inspector decide my plan is not acceptable.